


they whisper in the hallway (she's a bad, bad girl)

by pirateygoodness



Category: The Flash (TV 2014)
Genre: F/F, First Time
Language: English
Status: Completed
Published: 2019-11-22
Updated: 2019-11-22
Packaged: 2021-02-25 22:47:59
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,836
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21523195
Author URL: https://archiveofourown.org/users/pirateygoodness/pseuds/pirateygoodness
Summary: Caitlin sits, taking stock of the situation. Her bed is covered in a thin but definitive layer of ice, steam rising as the cold from it hits the heat of her bedroom. Judging from the pool of icy water underneath her, soaking through her pyjamas, her bed has been frozen for a while. Long enough for her body heat to partially melt it, at least. Lying next to her, snoring gently, is Killer Frost."Impossible," Caitlin whispers. The room and Killer Frost say nothing.+(or: Caitlin and Frost finally get their own bodies)
Relationships: Killer Frost & Caitlin Snow, Killer Frost/Caitlin Snow
Comments: 14
Kudos: 189





	they whisper in the hallway (she's a bad, bad girl)

**Author's Note:**

  * For [fivewhatfive](https://archiveofourown.org/users/fivewhatfive/gifts).



> Gift fic for isaidquirky, who loves these two possibly more than I do. Title from Taylor Swift's "Miss Americana and the Heartbreak Prince" because it needed to be.

Caitlin wakes up cold. Ice cold, the kind that settles in her bones and that turns her nose and fingers numb, leaves her shivering and curling in on herself. She hasn't felt cold like this in - she doesn't remember how long. 

(One of the benefits to having an ice-powered meta human sharing her body has always been that she never needs to dress for the weather.) 

She opens her eyes, and the first thing she sees is white hair, curling around ice-pale skin. It's hard underneath her; she pats at the sheets. Her bed is frozen over. 

Caitlin wakes up a little more. 

She sits, taking stock of the situation. Her bed is covered in a thin but definitive layer of ice, steam rising as the cold from it hits the heat of her bedroom. Judging from the pool of icy water underneath her, soaking through her pyjamas, her bed has been frozen for a while. Long enough for her body heat to partially melt it, at least. Lying next to her, snoring gently, is Killer Frost. 

"Impossible," Caitlin whispers. The room and Killer Frost say nothing. 

She slips out of bed, pads across the floor on tender, chilly feet until she feels the crunch of light frost and then cool carpet and then warm floor, unfrosted. "What in the world," she whispers to herself. This shouldn't be happening. This _can't_ be happening. Killer Frost is a part of her. They share DNA, share a body, share _everything_ and now the piece of Caitlin's heart that housed Killer Frost is outside of her body entirely, snoring gently and icing up her bed. 

Caitlin shivers, very suddenly. Her body isn't tolerant to cold anymore, and she can feel an awful, painful tingling in her thighs and feet as blood starts to return to them. She hadn't even realized they were numb. The first step is to get out of her wet things. 

She tries to move along the edge of the room as delicately as she can. Her feet are clumsy and a little numb; the best she can manage is a series of cautious steps. There's a sweater resting on top of her dresser, the one she wore yesterday, and yesterday's jeans and socks in her laundry hamper. She thinks back to med school, tries to recall approaches to re-warming but she's so cold that she can hardly think straight. 

Shower. That's what she needs. A warm shower, and dry clothes, and maybe a cup of tea to clear her head. 

+

"It's okay," Caitlin whispers into the empty kitchen. She's waiting for the kettle to boil, shivering even in her sweater and jeans. She found two throw blankets in the living room and she's got one draped around her shoulders, the other around her waist like a fuzzy woolen wrap skirt. The shower helped, and the dry clothes helped _tremendously_ , but she still feels chilled through. "Everything's okay."

The kettle is making noises like it's nearly finished. She stands to fetch a mug and a teabag. "So we woke up and Killer Frost was outside of us. That's - fascinating. It's an interesting scientific phenomenon and it's going to be fine." 

Somehow, she doesn't feel reassured. 

\+ 

Three cups of tea and another hot shower later, Caitlin finally feels warm. It's morning now, the clock on her microwave reads 9 AM. 

She's late for work, but she feels like Barry and Cisco will understand. 

She's waiting for the toaster to finish making her toast, scrolling aimlessly through her phone. She can't focus, can't think about anything just yet. It sort of feels like her head is exploding. 

(Metaphorically of course. If her head were _literally_ exploding she probably wouldn't feel anything, and unread emails would be the least of her worries.)

It feels like she's moving through a fog. Like nothing is quite real, because it can't be real, because Killer Frost isn't inside her anymore and also her mattress is frozen solid because Frost iced it in her sleep and what are the odds that the metahuman clause in her insurance policy will cover a new one. 

There's a noise, coming from the doorway to the bedroom. 

Caitlin's body hears it before her brain has a chance to do any damage control: she jumps about a foot and throws her phone onto the counter. It lands with a clatter, narrowly missing the sink. 

Killer Frost is awake. She's leaning against the door frame, real and substantial. It's the oddest thing, seeing her like this. Caitlin's used to Killer Frost in action, from the footage on the news or the dressed-to-kill selfies she finds in her phone. She's not used to this Killer Frost, the one rubbing sleep out of her eyes, drowsily smearing blue-and-white glitter across her temples. She's wearing the super suit, the one Cisco made. In context, while Killer Frost yawns barefoot on Caitlin's kitchen floor, the costume seems out of place. 

"Caity?" she says. She doesn't sound like Killer Frost: Metahuman Friend of The Flash. She sounds like KF, the girl who sends Caitlin thoughtful post-it notes, who restocks the fridge when Caitlin's having a stressful week and teases her to bring her back down to earth when her worries get the best of her. She runs a hand through her hair, pulls it away from her face and curls a strand around her index finger, absently. "What happened?" 

Caitlin doesn't know how to begin to answer that question. 

The toaster finishes its job with a satisfying, metallic click. Two pieces of toast pop up, perfectly cooked. "Sit down," Caitlin says, as she puts the toast on a plate and passes it over to - Frost. That seems like a better name to call her; the "Killer" epithet is hardly apt. "I'll make you a cup of tea." 

+

They make a timeline. 

It takes an hour, four cups of tea between them, and a round of toast with peanut butter (for Caitlin) and Nutella (Frost). More data should be helpful; it should give Caitlin a clue about what happened to them. 

Instead, it feels like things only get muddier. The past week has been perfectly, frustratingly ordinary. No exposure to untested medical devices, no experimental radiation. They haven't encountered any new metahumans with unpredictable powers lately. 

It's like the universe just turned around late last night and decided they should be split in two. 

\+ 

Caitlin takes Frost to work. 

Frost spends most of the morning - after the inevitable hey-guys-how's-your-Monday-going-Frost-and-I-have-two-bodies-now team meeting - doodling in the blank pages of Caitlin's lab notebook. Caitlin spends most of it running genomic analyses to sort out what could possibly have happened. 

It lasts until about 30 minutes before noon. Frost has spent the last ten minutes spinning in circles in one of the chairs, Caitlin finishing her assays and getting the sequencer set up to run. 

"Caity," Frost says. It's still strange to be able to hear her voice out loud, like this. Caitlin doesn't reply at first, just thinks to herself, _what now?_

After a long beat, Frost rolls her eyes. " _Caity._ You have to answer with your face, I'm not in there anymore." She reaches across the lab bench and taps Caitlin's temple with an icy fingertip to punctuate. 

Caitlin sighs. "Yes, Frost. How can I help you?"

Frost looks down at the assays. "Those are almost done. Let's go for cheeseburgers." 

It stops Caitlin cold. They are almost done; there's one reagent left and then they can run on their own for the next four hours. She's run this assay millions of times, and logically she knows Frost must have seen her do it, but she just - she never thought Frost really paid attention. "I don't know," Caitlin says. Her inner sense of guilt is too strong, she's barely been at work for two hours and spent most of her day on a personal project no less, and going out for lunch with Frost isn't exactly - 

Caitlin's worries are cut suddenly short by Frost, taking her hands. She's surprisingly gentle, and her fingertips are warm against Caitlin's. "Come on," Frost drawls. She rubs at Caitlin's skin with her thumb and looks up with a pleading expression, her lower lip caught between her teeth. Something in Caitlin's chest squeezes. "You need to get out of your own head." 

"But we're still nowhere on sorting out what's happened between us, and it's - don't you want to know what happened? Make sure this doesn't have some unintended consequence?" 

Frost shrugs. "I guess," she says. "But I'm pretty sure I want a double cheeseburger with onions and pickles and a large fries and a vanilla milkshake first. If anything awful is happening, I'm sure it can wait for that." 

"Can't you take Ralph or someone? I bet Cisco would go with you, if you asked." 

She tugs at Caitlin's hands, gentle but insistent. "I don't wanna go with them," she says. 

_You_ is what her eyes say, and Caitlin gets that squeezing feeling in her chest again. _I want to go with you._

"Fine," Caitlin says, against her better judgement. "Just this once." 

Frost tugs Caitlin forward, overbalancing her just long enough for her to lean in and leave a blue-and-sparkle lipstick mark on Caitlin's cheek. That tension inside Caitlin's chest turns into a flutter. 

+

They sleep at Star Labs, that first night.

Caitlin's mattress is still drying out, and it doesn't feel fair to impose on one of her friends when there's a perfectly good pair of sofas at work. They push two of them together, front-to-front, into a makeshift double bed. 

Frost wears leggings and a black t-shirt to bed. It captures Caitlin's attention, the incongruence of her: her attitude still hard as anything but her outfit soft and almost cozy. Her arms are bare, and Caitlin must be staring - Frost crosses her arms over her chest first, then shrugs into the Star Labs hoodie Caitlin had left out for her. "You look -" Caitlin begins. 

"- stupid, I know," Frost says, finishing her sentence. 

"I was going to say cozy." Caitlin delivers the amendment as gently as she can. 

Frost ducks her head. She flicks her wrists so that the sleeves of her hoodie slide down overtop of her hands, cocooning them inside. "Oh," she mumbles. "Thanks, or whatever. You're cozy, too." 

Caitlin's already in her loungewear, finishing up some work in sweatpants and a tank top, with one of her warmest wool sweaters overtop. Something about the compliment - if that's what she can call it - makes her heart react, a little thrill of liking running through her. "Thanks," she says back.

Frost makes the bed, piling blankets and some spare sheets until their little sofa nest is as close as it'll ever be to Caitlin's bed at home. She settles in first, playing absently on Cisco's old 3DS until Caitlin's ready to sleep. 

Once they're both in bed, the space available to occupy feels shockingly small. They can't really sleep without touching; the couch backs behind them mean that the only space to spread out is toward each other. 

Frost settles in with a sprawling presence, one knee up and one arm already draped across the top of the sleeping space, above Caitlin's head. It's strange. Sharing a body is probably the most intimate experience two people can have; anything less should feel perfectly natural. But the reality of Frost like this - flesh-and-blood, breathing softly into the air between them, one knee pressed against Caitlin's hip - feels like something far more intimate than Frost being inside her. It's oddly dissonant, sharing a bed with someone who is somehow a close friend and a stranger at the same time. "You comfy?" Frost whispers. 

Caitlin nods, realizes that Frost probably can't see it in the dark, then hums in the affirmative. "Hey," she whispers. "Don't ice out on me again." 

She's already getting drowsy, her voice sleep-rough around the edges. She hears the rustle of sheets beside her, and then feels the gentle weight of Frost's hand on her hip. Frost pulls, urging Caitlin over until they're spooning, Caitlin's back to Frost's front. "Don't worry," Frost whispers. "I've got you." 

Caitlin's exhausted. That's what she'll tell herself. 

It doesn't have anything to do with the way Frost's body fits neatly up against hers, or the warm, safe feeling that comes from Frost pressed to her back. It's just been a long day, that's all. 

+

They sleep together every night, after that. 

+

It's two more days before Caitlin has a breakthrough. 

The genomic analysis didn't get her anywhere, nor did the dark matter readings, but there's something hidden in the timeline that she'd overlooked before, and - "Oh." 

Frost looks up from her comic book - no, her _trade paperback_ \- with a vague look of interest. "Can I help you?" she says. 

It's endearing, at this point. They've been split for three days now, and spent most of it in the same room. Frost is blunt, but Caitlin can see all the little ways she cares. And honestly, it's been nice to have some new company in the lab. 

"I've got it," Caitlin says. "I think I know how we got split. Which means, in theory, I could figure out how to put us back together again." 

"Congratulations," Frost says. Her voice is flat, and she doesn't say another word as she picks up her coat and stomps out of the lab.  
+

Caitlin doesn't see Frost for over a day.

She'd be lying if she said she didn't spend most of that time fretting. She goes to the mall, looks at options for mattresses to keep her mind off of things. 

She tries not to think about the way it feels like she should be checking in with Frost before she buys a new one. 

+

Caitlin works late the next night. She doesn't particularly need to; she could easily take the night off and finish things up in the morning. But she has this feeling, a shiver down the back of her neck that tells her she should linger. 

Just as she's finishing up, Frost appears in the doorway. 

Frost has a new jacket on, black denim, and she's wearing a band t-shirt with a flames-and-skulls logo that Caitlin doesn't recognize. "Hey," she says. She sounds softer and smaller than Caitlin has ever heard her. 

But it's not - she can't just do that. She can't just leave and then reappear whenever she wants, like a stray cat. She left and Caitlin _worried_ and all of the anxiety comes out in her voice as she replies, "You're done sulking now?" 

Frost rolls her eyes. "Don't be like that," she says. 

"Don't be like what? Concerned for your welfare? Interested in knowing where you were or why you stormed off like a teenager without even _talking_ to me?" Caitlin can hear the edge to her voice, her worry sublimating into concern and outrage that feel like the beginnings of an argument. 

Frost keeps her cool. Caitlin's not too angry to appreciate the aptness. "Look," Frost says. She crosses the room as she speaks, her boots heavy on the floor. "I left because I don't want you to put us back together." 

"Why not?"

Frost puts her fingers underneath Caitlin's chin and Caitlin knows where this is going, feels it deep inside herself, inevitable. It's always been this. It's always been them. "If we're in the same body, I can't do this." 

Caitlin wants to say something more. Some little joke, a teasing comment to punctuate Frost's words. But before she can get the words out, Frost is covering Caitlin's mouth with her own and they're kissing and it's _perfect._ All of Caitlin's irritation melts away. 

Their kiss is an ending and a beginning all at once, the end of the two of them as Caitlin-and-Frost and the beginning of something like _them._ Frost's lips are warm and soft and she's surprisingly gentle as she works against Caitlin's mouth. Caitlin melts into it, smiles to herself both at the pun and the feel of this coming together. 

Frost reacts to her smile, pulls away and scans Caitlin's face with wide, concerned eyes. "Is that okay?" she asks. 

"More than okay," Caitlin says. "It's perfect." 

"Don't put us back together, Caity," Frost mumbles. She's playing with the collar of Caitlin's shirt, fidgeting at the fabric with her fingertips. It's creating a suggestion that Caitlin feels with her whole body, a slow bloom of desire filling her up. "Not unless you have to." 

Caitlin kisses Frost this time, long and slow. "Okay," she says, her lips still pressed to Frost's mouth. "I won't." 

"Good," Frost sighs. There's not a hint of ice to it; her breath is warm and her body is warm in Caitlin's arms. They kiss again and again, long enough that Caitlin loses track of how many kisses it's been or who started it. They're just kissing each other, and it's been so long since Caitlin's been kissed this well or this long that she can't help but feel it. 

Caitlin isn't a stranger to her own desire, but usually it's something to be handled privately. (Or, occasionally, with Frost following along in her head.) It's almost unfamiliar, the feeling of being aroused with another person pressed this close to her. A brief moment of uncertainty, of anxiety at the thought of - being intimate - with Frost rears its head. 

But there's something about Frost that's just so - honest, that's the word. Her tells are nothing like Caitlin's. Caitlin expresses her desire softly, with gentle whimpers and thighs pressed together. Frost shows her desire on her sleeve, wrapping her leg around the backs of Caitlin's thighs and rubbing up against her. Caitlin knows exactly where Frost stands, can see the way that Frost is sighing and the catch of her breath and it makes her feel safer. More certain, anyway. 

"Caity," Frost whimpers. 

"Yeah?"

Frost whimpers again, runs her hands across Caitlin's back. She presses them flat, pulling Caitlin forward so that they're pressed as close together as they can be, front to front. Frost's leg is up around Caitlin's waist now; she's holding herself open with her groin pressed as close as it can be to the fly of Caitlin's jeans. "Caity I want to -" 

It feels too fast. It also feels like just fast enough. They've just kissed for the first time today, and Caitlin doesn't _do_ this. She doesn't have sex on the first date or even the third, sometimes. She needs to warm up to someone, to ease her way into things. 

But with Frost, it feels alright. It feels like they've been easing into this for years, the culmination of an endless courtship. Caitlin takes her hand from around Frost's waist and slides it into the narrow strip of space between their bodies, along the inseam of Frost's jeans. "Me too," Caitlin whispers. "If you want to." 

Frost reacts with her whole body, rubbing her hips down against the firmness of Caitlin's fingertips. Caitlin can feel the heat of her through her clothes, the warmth that comes from a physiologic arousal response that Caitlin can feel mirrored in her own groin. 

(Well, more specifically, the inside of her vaginal canal and the apparatus of her clitoris; working to create increased lubrication and sensitivity.) 

(Even more specifically, Caitlin's wet beyond belief and her clit is aching; from Frost's body language she's fairly certain that Frost feels something quite similar.) 

"I want to," Frost whispers. "Caity, I need to." 

There's something about the word _need_ that works for Caitlin. It's not true, not technically. There's no physiologic imperative for sexual release. They'd both be fine if they went back to their workstations and cooled off. But Caitlin understands that feeling, that complex blend of desire and emotion building in urgency until it feels like it might as well be biologically necessary. "Okay," she whispers. "Okay, I've got you." 

Nowhere in the lab is suitable - or safe - for sex. Caitlin's sure of that. But their bed is still made in the break room, and it's late enough that everyone else has left for the night. Barring any sudden city-wide emergencies, they should have the space to themselves. "We should find a bed," Caitlin says. 

Frost kisses her, long and deep and slow. "Yes," she hisses. "Fuck, yes." 

They find a bed. 

It takes them longer than it really should, but then, Frost keeps stopping them to kiss in the hallways and Caitlin keeps letting her. The bed is there, blissfully empty, as she sees it Caitlin's struck with a sudden wave of desire. She wants this, so badly. She wants to _get laid_ , in a way that she hasn't wanted in years. 

Frost is holding her hand and she stops at the edge of the bed. Her pupils are dilated, and Caitlin can see her breath coming faster, the delicate flush to her cheeks. "So, there, uh. There's a slight chance that I haven't done this before," Frost says. 

"I mean, me neither." Caitlin gives Frost's hand a reassuring squeeze. 

"But in college there was -" 

"We didn't do _this._ " Caitlin clarifies. 

Frost pauses for a minute, and Caitlin watches as the realization hits her. "Oh," she says. " _Oh,_ so you're gonna -" 

"If you want." 

Frost pulls Caitlin close, somehow managing to turn held hands into her arm around Caitlin's waist and the two of them front to front. "I totally want that," she drawls, before she drags Caitlin into yet another kiss. 

They do that.

They slip into their makeshift bed, naked under the blankets, mirror images of each other. It feels strange until it doesn't, until it feels like the most natural thing in the world to slip her hand in between Frost's legs, to feel the slick warmth of her and watch the way she sighs. That feels good. 

When Frost looks up at Caitlin through her eyelashes, her smile suddenly wicked, and walks her fingertips up Caitlin's thighs and in between her legs, that feels best of all. 

They fit together like puzzle pieces. Like it's what they were meant for. They fit together warm and slick and sweaty and whimpering. When Frost comes first, she exhales a little puff of snow over Caitlin's shoulder. The chill of it makes Caitlin shiver and shudder and fall over the edge herself. 

They finish and they rest, nose to nose. The space around them is humid and it smells like sex and Caitlin can't imagine wanting to be anywhere but here. "We should put some clothes on," she whispers, half-heartedly. 

Frost pulls Caitlin closer, closing the embrace until Caitlin's head is tucked against the swell of her breasts. "It's okay, Caity," she sighs. "Let's just stay like this for a while." 

"Alright," she says. "Okay." 

She can feel herself getting pulled into sleep, the exhaustion of her long workday and the afterglow overtaking her. She falls asleep warm, cuddled into Frost's arms, and it feels like everything is exactly as it's supposed to be.


End file.
